The Equal Rights Amendment (ERA) was a proposed amendment to the United States Constitution intended to guarantee equal rights for women. First introduced in Congress as early as 1923, and submitted repeatedly over subsequent years, the ERA finally passed both houses of Congress in 1972, and it was sent to state legislatures for ratification. Congress set a ratification deadline of June 30, 1982, but the amendment failed to receive the necessary number of ratifications before the deadline, and thus the ERA was not adopted. There have been many attempts to revive the ERA. Throughout its long history, the ERA experienced substantial activism by both supporters and opponents, sometimes accompanied by large shifts in political attitudes.